Hammer mill with concentric screens for separating varied sizes of finished materials



June 19, 1951 P. A. EMMANOUILTDIS 2,557,865

um um. wrm concaumc SCREENS FOR ssam'rmc VARIEP SIZES 0F FINISHED MATERIAL 2 Sheets-Sheet 1 Filed March 9, 1949 In um tor m N Pa/ychronis A. E mmanoui/idis MWWEMW June 19, 1951 P. A. EMMANOUILIDIS 2,557,865

- mum wrm coNcEm'RIc scxzsns FOR SEPARATING mama $1225 or FINISHED MATERIAL Filed March 9, 1949 2 Sheets-Sheet 2 lnvmtar tome Polyclrronis A. Emmanoui/Mis Fig. 8.

Patented June 19, 1951 FFICE HAMMER MILL WITH CONCENTRIC SCREENS FOR SEPARATING VARIED SIZES OF- FIN ISHED MATERIALS Polychronis A. Emmanouilidis, Quantico,

Va., as-

signor ol' twenty-five per cent to John P. Pandazides, Quantico, Ya.

Application March 9, 1949, Serial No. 80,412

2 Claims. (Cl. 241-86) This invention relates to new and useful improvements and structural refinements in hammer mills, that is, mills wherein the material to be milled is delivered into a chamber containing a rotor rotating at high speed and carrying a plurality of hammers, these hammers impacting the material and breaking the same into fine particles.

The primary object of the invention is to provide a mill of this type which is extremely efficient in operation, simple but durable in construction and which may be used for milling materials of various types.

An important feature of the invention resides in the provision of a plurality of concentrically disposed foraminous cylinders which surround the rotor and facilitate separation of the milled material in accordance with different degrees of fineness, each grade of the milled material being discharged through a separate outlet, whereby the mill may be used for producing several different grades of material at the same time.

Another feature of the invention resides in the structural arrangement of the foraminous cylinders and their housing which permits convenient and expeditious access to the cylinders for purpose of cleaning and removal, the cylinders being readily removable and usable either singly or in multiple, depending upon the requirements of the work.

With the above more important objects and features in view and such other objects and features as may become apparent as this specification proceeds, the invention consists essentially of the arrangement and construction of parts as illustrated in the accompanying drawings, in which:

Figure 1 is a vertical cross sectional view of the invention,

Figure 2 is .a cross sectional view, taken substantially in the plane of the line 22 in Figure 1,

Figure 3 is a perspective view showing one of the assemblies of cylinder half sections,

Figure 4 is a perspective view of the rotor used in the invention, the same being shown in association with a shaft,

Figure 5 is a fragmentary elevational detail, taken substantially in the plane of the line 5-5 of Figure 1,

Figure 6 is a fragmentary cross sectional view showing a gasket on the edge on one of the cylinders,

Figure '7 is a diagrammatic view of an indieating mechanism used in the hopper of the invention for issuing a warning signal when the contents of the hopper are nearly exhausted, and

Figure 8 is a wiring diagram of a magnetic detector system used in the invention for in:

dicating the presence of foreign objects in the material.

Like characters of reference are employed to designate like parts in the specification and throughout the several views.

Referring now to the accompanying drawings in detail, the invention consists of a hammer mill designated generally by the reference character III, the same embodying in its construction a housing l2 consisting of a pair of complementary sections, namely, the upper section l4 and the lower section l6, these sections having their contiguous edge portions provided with suitable clamps 18 whereby the sections are separably secured together, as will be clearly apparent from Figure 2.

The lower section ii of the housing [2 is provided on the exterior thereof with a pair of brackets 20 carrying suitable enclosures 22 for a pair of axially aligned anti-friction bearings 24, the bearings 24 accommodating a horizontal shaft 26 which extends transversely through the housing I! and carries a rotor 28.

It should be understood that the enclosures 22 for the bearings 24 are so arranged that the enclosures may be opened to facilitate removal of the bearings together with the shaft 28 and rotor 28 after the housing section l4, IE are separated.

The shaft 26 also carries a pulley 30 which is rigidly secured thereto and an additional pulley 32 which is freely rotatable thereon, the pulleys 30, 32 being disposed in side by side relation so that a belt may be engaged with the pulley 30 for rotating the rotor 28 but may be shifted laterally to the pulley 32, in which event no rotation will be imparted to the rotor.

The rotor assembly 28 consists of a cylindrical body 34 which is rigidly secured to the shaft 26 and is provided with a plurality of longitudinally spaced diametrically extending bores 36 adapted to receive inner end portions of a set of radially extending arms 38. A set of fastening elements such as the screws 40 extend longitudinally through the body 34 and rigidly secure the arms 38 in position, the outer ends of the arms being equipped with enlarged heads 42 so that the arms, together with the heads, constitute what may be referred to as hammers.

A foraminous separating screen 44 is mounted in the housing I2 in a manner hereinafter to be described, this screen surrounding the rotor assembly 28 in spaced concentric relation and defining what may be referred to as a milling cham-- ber 46 in the housing, wherein the rotor assembly is located..

A plurality of additional separating cylinders 48, 50, etc. of foraminous construction are provided in the housing I2 in spaced concentric relation relative to the cylinder 44, the cylinder 44 being the innermost and the outermost cylinder (50) being spaced from the housing, as is best shown in Figures 1 and 2.

The spaces between the cylinders 44, 48, 59 and the cylinder 50 and the housing I2 constitute. a plurality of annular collecting chambers 52, 54, 56 having respective outlets 58, 68, 62 which extend outwardly from the housing I2. as shown.

The upper section I4 of the housing is equipped with a suitable hopper 64 which communicates by means of a gravity feed duct 66 with the milling chamber 46, the duct 66 entering the chamber 48 laterally as shown in Figure 1, so that the material delivered from the hopper 64 through the duct 66 is impacted by the rotating hammer heads 42 of the rotor assembly 28 and is broken down into fine particles. It should be explained at this point that the openings in the foraminous cylinder 44 are larger than the openings in the next adjacent outer cylinder 48, and the openings in the latter are, in turn, larger than the openings in the next adjacent outer cylinder 50, so that as the material in the milling chamber 46 is broken down, relatively large particles of material will pass through the foraminous cylinder 44 into the chamber 52 and out of the duct or outlet 58, while somewhat smaller particles will pass through the foraminous cylinder 48 into the chamber 54 and out of the duct 60, while even smaller particles will pass through the cylinder 50 into the chamber 56 and out of the duct 62. In this manner the same milling operation will produce three difierent grades of material, that is to say, three difierent grades of fineness of material, and each grade may be collected separately by virtue of the individual outlets 58, 68, 62.

The rate of flow of material from the hopper 64 through the duct 66 into the chamber 46 may be controlled by means of an adjusting screw 68 having a head I0, the position of this head relative to a graduated scale I2 on the hopper 64 indicating the adjustment of the screw, as will be clearly apparent. If desired, the screw '68 may be used for actuating a gate valve, or the like, in accordance with conventional practice.

To facilitate convenient assembly and removal, each of the cylinders 44, 48 and 50 may consist of a pair of complementary half sections as illustrated in Figure 3, the half sections of the cylinder 44 being provided with a set of abutting straps I4 which, in turn are secured by angle brackets I6 to the housing section I6. The half sections of the cylinders 48, 50 are, in turn, removably secured to the straps I4 as at It, 80 respectively, by which arrangement only the cylinder 44 may be used, or the cylinders 44, 48 employed in unison, or all three cylinders 44, 48, 58 used in unison, as required by the nature of the work. Moreover, the formation of the cylinders in two sections, secured together by the abutting straps I4, permits the top sections to be'removed as a unit after the housing section I4 is separated from the housing section I6, after which the rotor assembly 28 may be simply lifted out of its bearings and the lower cylinder sections may then be removed, for purposes of cleaning or inspection of the mill as a whole.

It is to be noted that the side edge portions of the cylinders 44, 48, 58 are provided with resilient, substantially semi-circular gaskets 82 which frictionally engage the sides of the housing I2 and prevent the material from escaping from one chamber to another other than through the foraminous cylinders.

If desired, means may be provided for warn ing the operator when the material in the hopper 64 reaches a predetermined low level, such means involving the provision of a cross member 84 in the hopper and an electric switch 86 on the cross member, as illustrated in Figures 2 and '7. The switch 86 includes a pivotally mounted arm 88 carrying a length of chain 90 on which, in turn, is suspended a weight 92, the weight 92 resting on top of the material in the hopper and descending downwardly therewith as the material is discharged through the duct 66. The switch is normally opened but when the descending weight 92 causes the arm 88 to descend to a predetermined level, the switch 86 is closed and energizes a suitable bell 94 which is connected in series with the switch 86 to a battery 96. In this manner the operator of the machine will be audibly warned as to the need for refilling the hopper, as will be clearly apparent.

The invention-also embodies in its construction means for detecting the presence of foreign objects, particularly metallic foreign objects in the hopper 64, which objects, if permitted to gravitate through the duct 66 into the chamber 46 may result in considerable injury to the rotor assembly 28. These means involve the provision of a pair of magnetic detectors 98, I08, the former preferably being positioned on the bottom of the hopper 64 while the latter is positioned in the duct 66, as shown in Figure 1.

Each of the detectors 98, I00 consists-of a pair of spaced permanent magnets I02, I04, the latter being connected in series to suitable indicating lamps I06. On the other hand, the magnets I82 are connected to a battery I08, and it will be It is believed that the advantages and use of Q the invention will be clearly apparent from the foregoing disclosure and accordingly, further description thereof at this point is deemed unnecessary.

While in the foregoing there has been shown and described the preferred embodiment of the invention it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

Having described the claimed as new is:

1. In a hammer mill, the combination of a housing comprising upper and lower sections having respective lower and upper contiguous invention, what is edges thereof separably secured together, a pair of coaxial bearings mounted exteriorly on oppo- 'site sides of the lower housing section and having their axis disposed in the plane of said contiguous edges, a rotor mounted in said housing and including a transverse shaft rotatably journaled in said bearings, said bearings including removable upper caps whereby to permit removal of said rotor and shaft when the housing sections are separated, a set of horizontal straps secured to the upper edge portion of the lower housing section and disposed at the opposite sides of said rotor in the plane of said contiguous edges, and a plurality of foraminous stationary separating cylinders provided in said housing and surrounding said rotor in spaced concentric relation, each of said cylinders comprising upper and lower half sections having opposite ends thereof removably secured to said straps at respective opposite sides of said rotor.

2. The combination as defined in claim 1 together with arcuate gaskets provided at opposite side edges of the separating cylinder half sections and engaging inner surfaces of the respective sections of said housing.

POLYCHRONIS A. EMMANOUILIDIS.

8 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 87,716 Smith Mar. 9, 1869 133,111 Mitchel Nov. 19, 1872 212,664 Davis Feb. 25, 1879 247,749 Dawson Oct. 4, 1881 505,849 Rasell Oct. 3, 1893 516,367 Cook Mar. 13, 1894 604,283 Albrecht May 17, 1898 745,450 Meyer Dec. 1, 1903 1,018,440 Paul Feb. 27, 1912 1,028,867 Emerick June 11, 1912 1,147,283 Tuttle Feb. 20, 1923 1,446,221 Starr Feb. 20, 1923 1,554,976 Kearns Sept. 22, 1925 1,698,758 Knittel Jan. 15, 1929 1,768,713 Prater July 1, 1930 FOREIGN PATENTS Number Country Date 181,020 Canada June 19, 1917 

